When ventilation or Personal Protective Equipment (PPE) are used to protect workers from air contaminants, air sampling must be conducted to ensure those workers are not overexposed. Verifying that controls are adequate is critical. Air sampling for levels of air contaminants can give an organization concrete evidence and peace of mind, but how should it be done?
It is important to have a strategy for many of the activities that we do each day. Whether grocery shopping, scheduling rides for football and soccer practices – or completing a job safety analysis – having a clear plan of attack is necessary to complete the needed tasks. Air sampling is no different in that an effective strategy can prove employees are properly protected or indicate that greater protective measures are required.
Whether the air sampling is contracted through an outside vendor, or conducted internally, the strategy must consider who will wear the air sampling pumps, where and when the highest concentrations of a contaminant are present, what contaminants will be tested for and why. Since OSHA’s Permissible Exposure Limits (PELs) are calculated as an 8-hour time-weighted average, air sampling of the entire shift is essential. When employees work 10-hour days, or longer, the air sampling duration must be increased accordingly, and the PEL calculations are adjusted to account for the increased exposure.
Document work activities and environmental conditions as air sampling should represent the highest concentrations of air contaminants across a full work shift. Factors to consider are the amount of work being performed, location of both local and general ventilation sources, and proximity to other possible contamination sources. As for how often to conduct sampling, a general “rule of thumb” is to test in the summer when most buildings have a large amount of outside air circulation, and in the winter when outside air circulation is minimized in order to conserve heat.
For more information on this topic sign up for MEMIC’s webinar scheduled for October 16, 2014, by clicking on the following link: Air Sampling Strategies